v.i.c.s-shutter valve

[dodson3]

Does anybody know what exactly the shutter valve does?my car is really pissing me off,it idles like crap and sometimes it runs horrible.it will run fine & then all of a sudden it will hesitate and jerk while driving.I was checking my vaccum hoses & messed around with the shutter valve.It was idling up and down till I pulled the actuater rod out,then it idled fine.I disconnected the hoses to feel for vaccum and they checked out.the vaccum hoses from the shutter valve go to a solenoid or something,it has an eletrical connecter hooked to it.my haynes manual doesn't say much so I had to ask,it's really getting annoying.

[OCD-SPEED]

It manages the length of the path that the air takes through the intake manifold. With the shutter closed (at low RPM) the path is longer and makes more torque. After a certain RPM 4500RPM i think, the shutter opens and allows maximum horsepower.

As for your problem. I just put a BP in my protege and it idles up and down and then sometimes stops. My problem sounds alot like yours. I have yet to figure out what the hell it is, but i dont think its vics related.

[dodson3]

i THINK i may have found my problem.a vacuum hose connected to the back of the intake manifold had a small crack in it.i replaced it and let my car idle for awhile.it idled good but i didn't drive it yet.--not related--->i noticed when i push in my brake pedal the rpm's drop and when i let off it they rise up again.it seems electrical to me,bad grounds maybe.the brake lights shouldn't be drawing that much power.it also does this when i press in the clutch.

[charles]

Might want to check all the lines on the brake booster

[95ProLeila]

The phantom idle brake problem is pretty common, it's been discussed, I'm not sure if there's a fix or not.

[charles]

There is always a fix. The car didn't do that when it was new, did it?

[95ProLeila]

I didn't have it when it was new, so I wouldn't know. I don't remember who had the fix, maybe it was bruce, it's somewhere here. . . just do a search for "phantom idle"

[OCD-SPEED]

Miatas have that braking idle problem all the time. I was thinking putting a PVC valve in the brake booster line might stop it...but i dont know.

[95ProLeila]

No, it's simpler than that, someone did it. . . just dont know who